Abstract: The invention provides a means for discharging sediments by carrying them with the main water streams being released to the hydropower generators without the aid of any external supplied energy or pump and without wasting the useful potential energy of the water. The method of this invention can also be used for collecting valuable underwater mineral sediments from reservoirs or mountain lakes. With the addition of a fluid drive assembly, the effluent discharge system of this invention also facilitates powering of underwater dredging equipment or other underwater machinery for underwater work.